diff --git a/src/p_actionfunctions.cpp b/src/p_actionfunctions.cpp
index 1abe2c939..c6a6b20f4 100644
--- a/src/p_actionfunctions.cpp
+++ b/src/p_actionfunctions.cpp
@@ -988,6 +988,14 @@ DEFINE_ACTION_FUNCTION(AActor, A_SoundVolume)
 	return 0;
 }
 
+DEFINE_ACTION_FUNCTION(AActor, A_IsPlayingSound)
+{
+	PARAM_SELF_PROLOGUE(AActor);
+	PARAM_INT(channel);
+	PARAM_SOUND(sound);
+	ACTION_RETURN_BOOL(S_IsActorPlayingSomething(self,channel,sound));
+}
+
 //==========================================================================
 //
 // These come from a time when DECORATE constants did not exist yet and
diff --git a/src/s_advsound.cpp b/src/s_advsound.cpp
index a157adaa2..85db21c4b 100644
--- a/src/s_advsound.cpp
+++ b/src/s_advsound.cpp
@@ -53,6 +53,7 @@
 #include "serializer.h"
 #include "v_text.h"
 #include "g_levellocals.h"
+#include "vm.h"
 
 // MACROS ------------------------------------------------------------------
 
diff --git a/src/s_sound.cpp b/src/s_sound.cpp
index ab007ee06..fede842b1 100644
--- a/src/s_sound.cpp
+++ b/src/s_sound.cpp
@@ -1895,14 +1895,6 @@ bool S_IsActorPlayingSomething (AActor *actor, int channel, int sound_id)
 	return false;
 }
 
-DEFINE_ACTION_FUNCTION(AActor, A_IsPlayingSound)
-{
-	PARAM_SELF_PROLOGUE(AActor);
-	PARAM_INT(channel);
-	PARAM_SOUND(sound);
-	ACTION_RETURN_BOOL(S_IsActorPlayingSomething(self,channel,sound));
-}
-
 //==========================================================================
 //
 // S_PauseSound